Qld school warns berries used in tuckshop

A primary school in far north Queensland has warned parents their children may have been served smoothies at the tuckshop containing contaminated frozen berries.

Trinity Beach State School in Cairns has released a newsletter telling parents the school's canteen used Nanna's Mixed Berries to make smoothies for students.

The products have been disposed of and a list of symptoms distributed for parents, the newsletter says.

They're urged to take their children to the doctor if they begin showing any symptoms, which include fever, loss of appetite and stomach pains.

Queensland's education department has said three schools had reported using the potentially infected berries as of Wednesday evening.

Health authorities remain on the lookout for more hepatitis A cases, with 13 people in Queensland, NSW, Victoria and Western Australia having contracted the virus after eating the Nanna's and Creative Gourmet brands.

Cases could continue to be diagnosed for up to seven weeks depending on when people ate the berries, Australia's chief medical officer Chris Baggoley said.

Medical professionals say there's no need for people who ate the berries and still feel well to be tested.